When sample containers in which liquid samples such as serum, urine and blood-cell components are stored are set in an automatic analysis apparatus for clinical examinations, the sample containers need to be moved to a sample dispensing position of an analysis unit. In many analysis apparatuses, the sample containers are conveyed while the containers are mounted on a special rack dedicated to conveyance. The mechanism that conveys the rack is mainly made up of the following three types of modules separated by the functions thereof.
(1) A rack loading module which installs a rack mounted with a sample container
(2) A rack conveying module which moves the rack, which has been loaded into the rack loading module, to a sample dispensing position
(3) A rack storing module which collects and stores the rack whose sample dispensing has been finished
Japanese Unexamined Patent Application Publication No. 2000-105246 (Patent Document 1) discloses the techniques in which, in an automatic analysis apparatus employing the system that conveys racks on which samples are mounted, a loop-shaped rack buffer unit is disposed on a rack conveying line to store a plurality of racks, the stored racks are analyzed in an arbitrary order, and the racks are stored for an arbitrary period of time, thereby making it possible to analyze the sample, which needs to be preferentially analyzed, before the previously conveyed samples.